Field of the Invention
The present invention relates to a display device, and more particularly, to a touch integrated circuit (IC) and a display device integrated with a touch screen and using the same.
Discussion of the Related Art
A touch screen is a type of input device that is included in display devices such as liquid crystal display (LCD) devices, field emission displays (FEDs), plasma display panels (PDPs), electroluminescent displays (ELDs), and electrophoretic displays (EPDs), and enables a user to input information by directly touching a screen with a finger, a pen or the like while looking at the screen of the display device.
Particularly, the demand for display devices with an integrated in-cell type touch screen, which include a plurality of built-in elements configuring the touch screen for slimming portable terminals such as smart phones and tablet personal computers (PCs), is recently increasing.
In a related art display device with the integrated in-cell type touch screen disclosed in U.S. Pat. No. 7,859,521, a plurality of common electrodes for display are segmented into a plurality of touch driving areas and touch sensing areas, thereby allowing a mutual capacitance to be generated between the touch driving area and the touch sensing area. Therefore, the related art display device measures the change of a mutual capacitance that occurs due to a touch, and thus determines whether there is the touch.
In sensing the touch by using the mutual capacitive type, when a touched area is very small, it is difficult to sense the touch because a capacitance change is too small.
Specifically, in a pen touch input which is mainly used recently, since a pen touch area is far smaller than a finger touch area which is a typical input, it is difficult to sense a pen touch. Therefore, a separate pen touch input device is needed for sensing the pen touch.